Direct C(sp3)-N Radical Coupling: Photocatalytic C-H Functionalization by Unconventional Intermolecular Hydrogen Atom Transfer to Aryl Radical

Org Lett. 2020 Aug 7;22(15):6112-6116. doi: 10.1021/acs.orglett.0c02179. Epub 2020 Jul 20.

Abstract

An unconventional approach for intermolecular direct C(sp3)-N radical coupling has been developed by photocatalytic C(sp3)-H activation of simple alkyl substrates using O-benzoyl oximes. The selective photocatalytic energy-transfer-driven homolysis followed by decarboxylation generates the persistent iminyl radical and aryl radical, which would undergo an unprecedented intermolecular hydrogen atom abstraction from the alkyl substrate to provide the key C(sp3) radical. Selective radical-radical C-N cross-coupling furnishes imines which are valuable amine building blocks.